An examination of a butt weld is used to ensure the quality of the welding. It does not matter which method is used to butt weld the pipes or fittings, whether it is by means of contactless IR welding methods, by means of the classical butt welding method by touching a hot mirror, or another method, in accordance with the pipes or fittings to be welded, i.e., the dimensions thereof, the plastic thereof, the welding technology which is applied, etc., a weld seam is to have a specific shape or size, which can be visually examined. Guidelines or standards exist corresponding thereto, which precisely define how a seam should appear or how the permissible dimensions should be in relation to the pipe or fitting and welding properties, so that they meet the requirements. Up to this point, a manual visual judgment has usually been carried out by a responsible technician, who compares and judges the resulting weld seam on the basis of the standards and guidelines known thereto.
It is disadvantageous in this case that judgments by a technician are very time-consuming and therefore very costly. In addition, such a judgment is also not consistent, since human subjectivity plays a role and the examination is not always performed by the same technician.
JP 2000289115 A discloses an examination of a weld of plastic pipes by means of an ultrasound sensor, whereby a statement with respect to the melting of the pipe wall in the interior, which is not visible, can also be achieved. However, the high expenditure of this method is disadvantageous in this examination since such an examination is very time-consuming, because, inter alia, the weld must be completely cold before such an examination can take place, which is not ideal for the installation of a pipeline having diverse weld seams.